# Sukhoi Su-75 Checkmate

The Sukhoi Su-75 Checkmate (Russian: Сухой Су-75), also designated as the Light Tactical Aircraft (LTA; Russian: Лёгкий Тактический Самолёт - ЛТС, romanized: Legkiy Takticheskiy Samolyot - LTS), is a single-engine, stealth fighter aircraft under development by Sukhoi for export and for the Russian Aerospace Forces. The Sukhoi Design Bureau also designates the aircraft as T-75.

## Development

A static non-flying prototype was unveiled at the 2021 MAKS air show with President of Russia Vladimir Putin in attendance. The Checkmate's maiden flight was first scheduled for 2023 and then slipped to 2024 but then it got delayed to 2025, with initial deliveries planned for 2026–2027. The Checkmate is designed to be low cost and for export, and may compete with the Lockheed Martin F-35 Lightning II and Shenyang FC-31 aircraft of the same light to medium-weight category. Production is forecast to be 300 planes over 15 years.
According to the chief executive of Rostec, Sergei Chemezov, the LTS Checkmate is expected to cost US $25–30 million each.
Su-75 Checkmate development could be delayed due to international sanctions on Russia caused by the Russo-Ukrainian War, and Russia could not import semiconductors and high-tech machining equipment from the European Union. The potential export sales also stalled because Russia cannot trade using U.S. dollars.
In July 2023, analyst Maya Carlin of the Center for Security Policy wrote that sanctions against Russia, due to the ongoing invasion of Ukraine had slowed or stopped the aircraft's development. In particular noted was the loss of funding from the United Arab Emirates due to sanctions, which had been sustaining the Su-75's development, as the UAE seeks instead to acquire F-35s, with potential support from Israel.

## Design

The Su-75 has a diverterless supersonic inlet (DSI), a v-tail and internal weapons bays—all features intended to reduce radar signature. The wing area appears large, which has been interpreted by correspondent David Axe to imply that Sukhoi designed the fighter to fly and engage in combat at high altitudes—40,000 ft (12,000 m) or higher.
The angular ventral inlet, which wraps around the lower nose section, shares features with a DSI design concept first introduced in the Boeing X-32 aircraft. A diverterless supersonic inlet (DSI) is mechanically simple; DSI can reduce cost compared to more intricate inlet designs such as the McDonnell Douglas F-15 or Sukhoi Su-27. Instead of a conventional empennage, the Su-75 has a v-tail similar to that of Northrop YF-23. Instead of a set of elevators and a tail separately controlling pitch and yaw, a pair of combined ruddervators fulfil both roles. However, ruddervators require more sophisticated flight-control systems than conventional empennages.
According to the jet's designers, the Checkmate is designed to fly with a range of up to 3,000 km (1,864 mi), carry a payload of up to 7,400 kg (16,314 lb), and reach speeds of up to Mach 1.8 to 2.0. The fighter will also feature an internal weapons bay with five missiles and an autocannon.
Patents published in 2023 indicate that the initial design had been modified with changes to the fuselage sides, strakes and the air intakes to reduce radar signature. Mainly, the new design appears to have increased the lifting surface area of the airframe.

### Engine

The powerplant appears to be the Saturn izdeliye 30 engine which will also power the Su-57M variant. The izdeliye 30 is designed to be 30% lower specific weight than its AL-41F1 predecessor, and up to 18% more effective, with an estimated thrust of 107.9 kN (24,300 lbf) dry and 171.7 kN (38,600 lbf) in afterburner. Once in series production, the izdeliye 30 engine will have a much longer life span than other Russian engines.

### Cockpit

Due to restrictions preventing taking cockpit photos, NBC News Matt Bodner, the first Western journalist able to see the jet in person, provided a preview without a point of view photo. According to Bodner, the cockpit layout is identical to the Su-57 with a glass cockpit with two 38 cm (15 in) main multi-functional LCD displays similar to the arrangement of the Su-35S. The cockpit has a wide-angle (30° by 22°) head-up display (HUD).

### Avionics

The electronic infrastructure of the Checkmate is all open-architecture and makes use of "Matryoska" diagnostics systems that are mostly on-board. According to Yuri Beliy, the NIIP radar design bureau plans to develop a low-cost AESA radar for the aircraft. According to then-Deputy Prime Minister Yury Borisov, the Checkmate will share the same components and avionics as the Su-57 as a cost-reduction mechanism by the Sukhoi Design Bureau.

## Potential operators

Rostec is anticipating that Argentina, India, Vietnam and Iran will become the primary export destinations for the aircraft, with the African market also showing interest. In 2021 Sukhoi estimated the demand at 300 planes, and aimed to export the Su-75 to African countries over the following 15 years. At the SITDEF-2021 arms show held in Peru, Alexander Mikheev, the General Director of product export of Rosoboronexport, stated that there was interest in the Su-75 in a number of South American countries. In July 2023, Dmitry Shugaev, director of Russia’s Federal Service for Military-Technical Cooperation, confirmed that Nigeria was interested in the design. The jet has also been pitched for export to Turkey, Saudi Arabia and United Arab Emirates. Russia has also expressed interest in India participating in the Su-75 program. Some experts suggest India should consider the Su-75 due to it being a cheaper alternative than other multirole fighters such as the JAS 39 Gripen.

## Specifications

Data from Rosoboronexport, Flight Global, Breaking Defense, Suciu, Global security Lieser and Filseth
General characteristics
* Crew: one
* Length: 17.7 m (58 ft 1 in)
* Wingspan: 11.8 m (38 ft 9 in)
* Height: 4.0 m (13 ft 1 in)
* Max takeoff weight: 26,000 kg (57,320 lb)
* Powerplant: 1 × NPO Saturn AL-51F-1 (derivative) afterburning turbofan, 161.9 kN (36,400 lbf) with afterburner
Performance
* Maximum speed: Mach 1.8
** Mach 1.06, 1,300 km/h (702 kn; 808 mph) at sea level
* Range: 2,900 km (1,800 mi, 1,600 nmi)
* Ferry range: 3,000 km (1,900 mi, 1,600 nmi)
* Service ceiling: 16,500 m (54,100 ft)
* g limits: +8.0
* Rate of climb: 220 m/s (43,000 ft/min)
* Thrust/weight: 1.0:1
Armament
* Hardpoints: 5 internal, 6 external with a capacity of 7,400 kilograms (16,300 lb) maximum payload, with provisions to carry combinations of:
** Missiles: 3 x BVRAAM and 2 x SRAAM stored in the internal weapons bay, 6 × external, 2 × R-77, 3 × R-73, 2 × Kh-35E anti-ship missiles
Avionics
* Sh-121 multifunctional integrated radio electronic system (MIRES)
* Active electronically scanned array
* 101KS-V IRST system